package net.sahv.bdyz.util;
import java.io.*;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Date;
import java.awt.*;
import java.awt.image.*;

import javax.imageio.ImageIO;

import com.sun.image.codec.jpeg.*;
/**
 * 图片压缩处理
 * @author 
 */
public class ImgCompress {
	private static Image img;
	private static int width;
	private static int height;
	private static String path; //压缩后图片位置
	private static int proportion;
	@SuppressWarnings("deprecation")
	public static void main(String[] args) throws Exception {
		System.out.println("开始：" + new Date().toLocaleString());
		//ImgCompress imgCom = new ImgCompress("C:\\temp\\pic123.png","C:\\temp\\pic1234.jpg",4);
		initCompression("http://222.223.251.109:8087/yrsy/upload/clothPicture/syPicture/1472021488952.jpg","C:\\temp\\pic12345.jpg",4);
		System.out.println("结束：" + new Date().toLocaleString());
	}
	
	public static void initCompression(String inputPath, String outputPath, int pro){
		boolean flag=true;
		proportion=pro;
		/*File file = new File(fileName);// 读入文件
		System.out.println(file.exists());*/
		URL url;
		try {
			url = new URL(inputPath);
			img = ImageIO.read(url);      // 构造Image对象
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			
		}
		width = img.getWidth(null);    // 得到源图宽
		height = img.getHeight(null);  // 得到源图长
		
		//如果图片过小则不进行压缩。
		if(width<200){
			flag=false;
		}else if(height<200){
			flag=false;
		}
		
		if(flag){
			path = outputPath;
			try {
				resizeFix(width/proportion, height/proportion);
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		
	}
	
	/**
	 * 按照宽度还是高度进行压缩
	 * @param w int 最大宽度
	 * @param h int 最大高度
	 */
	public static void resizeFix(int w, int h) throws IOException {
		if (width / height > w / h) {
			resizeByWidth(w);
		} else {
			resizeByHeight(h);
		}
	}
	/**
	 * 以宽度为基准，等比例放缩图片
	 * @param w int 新宽度
	 */
	public static void resizeByWidth(int w) throws IOException {
		int h = (int) (height * w / width);
		resize(w, h);
	}
	/**
	 * 以高度为基准，等比例缩放图片
	 * @param h int 新高度
	 */
	public static void resizeByHeight(int h) throws IOException {
		int w = (int) (width * h / height);
		resize(w, h);
	}
	/**
	 * 强制压缩/放大图片到固定的大小
	 * @param w int 新宽度
	 * @param h int 新高度
	 */
	public static void resize(int w, int h) throws IOException {
		// SCALE_SMOOTH 的缩略算法 生成缩略图片的平滑度的 优先级比速度高 生成的图片质量比较好 但速度慢
		BufferedImage image = new BufferedImage(w, h,BufferedImage.TYPE_INT_RGB ); 
		image.getGraphics().drawImage(img, 0, 0, w, h, null); // 绘制缩小后的图
		File destFile = new File(path);
		FileOutputStream out = new FileOutputStream(destFile); // 输出到文件流
		// 可以正常实现bmp、png、gif转jpg
		JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
		encoder.encode(image); // JPEG编码
		out.close();
		
	}
}